Coupling component for transmitting medical substances

ABSTRACT

A coupling component is disclosed for transmitting medical substances, comprising two channels for conveyance of medical substances in two substantially opposite directions and a means for releasable connection to a second coupling component having a further channel for creating a coupling. The connecting means is a thread. A method for conveying medical substances to and from a container is also disclosed.

FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to a coupling component for transmittingmedical substances, comprising two channels for conveyance of medicalsubstances in two substantially opposite directions and a means forreleasable connection to a second coupling component having a furtherchannel, for creating a coupling. Furthermore, the invention relates toa coupling for transmitting medical substances, comprising a firstcomponent having two channels for conveyance of medical substances intwo substantially opposite directions, a second component having afurther channel and a means for releasable connection of the first andthe second component to each other for creating the coupling. Theinvention also relates to a method for conveyance of medical substancesto and from a container, in which method a coupling component having twochannels for conveyance of medical substances in two substantiallyopposite directions be connected to a second coupling component of acontainer, which second coupling component has a further channel.

The invention may be applied in different situations when medicalsubstances are to be handled, but hereinafter the particular, but not inany way limiting for the invention, fields of application constituting ameans for administration of fluids to/from infusion bags, which isdesired in medical treatment for instance, will be described forilluminating purposes.

Infusion bags are used for intravenous delivery of fluids and medicallyeffective substances to human beings and animals. For this reason, theinfusion bag is provided with an outlet through which fluid may flow toa component connected to the patient, such as a cannula or the like, andfurther into the body of the patient. When preparing the fluids whichare to be administrated to the body from the infusion bag, a usualmethod is that medically effective substances are supplied to apre-sealed infusion bag which is filled with a transport fluid, such asa sodium chloride solution or a glucose solution. The preparation isperformed by injecting the medically effective substance via an inletinto the bag.

For accomplishing the desired transportations of fluid a combined inletand outlet of the infusion bag together with a coupling device which isdenoted “spike” are often used. The spike has a first pointed end bymeans of which a membrane arranged in a narrow passage of the infusionbag, constituting inlet/outlet of the infusion bag, may be penetrated sothat the infusion bag be opened towards two channels arranged in thespike when the spike is introduced in the inlet/outlet of the infusionbag. One of the channels is intended for conveyance of fluid in adirection from the infusion bag towards the patient and the otherchannel is intended for injection of medical substances into theinfusion bag. In the other end of the spike are members arranged at themouths of the channels for connection to other components, such asflexible tubes for conveyance of the fluid further to the patient andcannulas for the injection of medical substances to the infusion bag.

However, it has appeared that during certain extreme conditions there isa risk that the spike, which by insertion in the above mentioned narrowpassage of the infusion bag is relatively loosely interconnected to theinfusion bag, may unintentionally come loose from the infusion bag ifthe equipment is handled carelessly or by carelessness in connectionwith other treatment of the patient. The system of spike and infusionbag is depended of the friction between the infusion bag and the spiketo prevent the spike from coming loose from the infusion bag.Furthermore, the spike has the disadvantage that leakage from theinfusion bag to the environment may occur when the spike is introducedand the membrane is penetrated. In some cases the fluids which are to beadministrated to the patient may be harmful to other persons than thepatient who has been prescribed the treatment as a result of anindication of a specific decease. This is particularly the case whenrepeated long-term exposure is concerned, which can happened to medicalstaff when preparing and connecting infusion bags every day if therequisite security regulations are not fulfilled. A further disadvantagewith the use of a spike which during the connection penetrates amembrane of the infusion bag for providing the fluid administrationchannels is that the connection step itself cannot be made in advance tolater on enable conveyance of fluid from the infusion bag to a receivingunit connected to the spike, but the channels have to be openedinstantaneously at the connecting moment.

THE OBJECT OF THE INVENTION AND SUMMARY OF THE INVENTION

One object of the invention is to provide a coupling component/couplingof the kind defined by way of introduction for transmitting medicalsubstances, in which coupling component/coupling at least some of thediscussed disadvantages of such previously known coupling devices hasbeen reduced to a great extent.

This object is achieved by providing a coupling component according toclaim 1 and a coupling according to claim 8. By a couplingcomponent/coupling having the feature that the connecting means is athread/a thread joint it is ensured that the coupling not beunintentionally uncoupled when the coupling is tension loaded. By meansof the thread/thread joint a coupling safe against tension load may beobtained at the same time as the connection may be accomplished quicklyand safely in one simple operation. This implies that in the use of adevice according to the invention, when an infusion bag is connected toa patient, an increased safety to the patient may be achieved at thesame time as it is possible to deliver medical substances to theinfusion bag and intravenously administrate fluid to the patient fromthe infusion bag. Furthermore the invention enables the use of othermeans, such as breakable fluid barrier plugs, for opening the infusionbag towards the channels and there is possible to ensure that leakage tothe environment is prevented by tightening the thread joint before theinfusion bag be opened towards the channels.

A further object of the invention is to provide a method of the kinddefined by way of introduction, in which method a container and acoupling component, having two channels for conveyance of medicalsubstances in two substantially opposite directions, may be connected toeach other for conveyance of medical substances via the channels withoutthe container being instantaneously opened towards the two channels.

This object is achieved by providing a method according to claim 17.Hereby the connection may be accomplished so as to later on enableconveyance of a medical substance from the container via one first ofsaid two channels and/or conveyance of a medical substance to thecontainer via the other of said two channels.

The invention also relates to an infusion bag according to claim 15 andan infusion arrangement according to claim 16.

SHORT DESCRIPTION OF THE DRAWINGS

A description in greater detail of exemplifying embodiments of theinvention will follow below with reference to the attached drawings.

In the drawings:

FIG. 1 is a sectional view of an infusion bag and a spike according toprior art connected to the infusion bag,

FIG. 2 is a sectional view of an infusion bag and a coupling accordingto the invention for transmitting medical substances, and

FIG. 3 is a sectional view illustrating a variant of the couplingaccording to invention in FIG. 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In FIG. 1 an infusion bag 1 and a coupling device 2 of the type calledspike according to prior art are illustrated. The coupling device 2 isprovided with a pointed part 3 which is introducible in a part 4 whichconstitutes an inlet/outlet of the infusion bag 1. This part 4 of theinfusion bag 1 is designed as a flexible tube with a circularcross-section corresponding to the cross-section of the pointed part 3of the spike and has, before the introduction of the pointed part of thespike, a seating membrane arranged at the mouth 5 thereof. In theintroduction of the spike the pointed part 3 penetrates the membrane andthe infusion bag 1 be opened towards two channels 6, 7 arranged in thespike. Thereafter, medical substances may be injected into the infusionbag 1 via one first 6 of the channels and fluid may be transported outfrom the bag via the other 7 of the channels to a receiving unit (notillustrated).

In FIG. 2 an infusion bag 10, a receiving unit 11 connected to theinfusion bag and a coupling 12 according to the invention areillustrated. The coupling 12 comprises a first component 13, a secondcomponent 14 and a means 15 for releasable connection of the first 13and second 14 components to each other for creating the coupling 12. Thefirst component 13 comprises a male fitting 16 provided with twochannels 17, 18 for conveyance of medical substances in twosubstantially opposite directions. One first channel 17 for injectingmedical substances into the infusion bag 10 and one second channel 18for conveyance of fluid out of the infusion bag 10 to the receiving unit11, which may be for example a chamber or the like for intravenoustreatment. The second component 14 is provided with a further channel 19intended to be in communication with said two channels 17, 13 of thefirst component 13.

The connecting means 15 is a thread joint having the characteristic thatsaid first 13 and second 14 components are locked against rectilinearmovement relative to each other when being connected to each other andthe coupling 12 is tension loaded. The first component 13 has a ring 20partly enclosing the male fitting 16, which ring has a internal thread21 constituting part of the thread joint. The ring 20 is concentricallyarranged relative to the male fitting 16. The second component 14comprises a female fitting 22 provided with said further channel 19 andan external thread 23 corresponding to said thread 21 of the ring 20 andconstituting part of the thread joint. When the first and secondcomponents are to be connected to each other, i.e. when the first andthe second components be screwed together, the male fitting 16 beintroduced into the female fitting 22 to form a connection between saidtwo channels 17, 18 of the first component 13 and the further channel 19of the second component 14, which connection is sealed relative to theenvironment. For this purpose the male fitting 16 and/or female fitting22 may be designed with a certain taper so that when the male fittingand the female fitting have been brought together a certain distance theouter surface 24 of the male fitting will abut against the inner surface25 of the female fitting, and then further movement of the components inthe introduction direction relative to each other is not longer possibleand a sealing between the male fitting 16 and the female fitting 22 isobtained when tightening the thread joint 15.

Although the coupling component according to the invention, i.e. saidfirst component, which has the both channels, is designed as a malefitting of the coupling in the illustrated example, in anotherembodiment it could be designed as a female fitting 22 a of the coupling12, such as illustrated in FIG. 3, and the other component, which isarranged on for example an infusion bag, would in such a case bedesigned as a corresponding male fitting 16 a. Of course it is alsopossible to change places of the threads in comparison to theillustrated embodiment in FIG. 2, so that instead, the second componentincluding the female fitting is provided with an internal thread and thefirst component including the male fitting is provided with an externalthread. The threads may for example be arranged on rings such asdescribed above.

Advantageously the design of the threads 21, 23, the male fitting 16 andthe female fitting 22 may be in accordance with a so called luer fittingcoupling such as in the illustrated embodiments.

The coupling component 13 according to the invention is provided with aport 26 for injection of a medical substance to the first of thechannels 17 and further conveyance of this substance to the infusion bag10. For this purpose, the first channel 17 has also an outlet 27arranged at one end of the first coupling component 13 which exhibitsthe connecting means 15 and the second coupling component 14 has saidfurther channel 19, which communicates with the first 17 and the second18 channels, for introduction or removal of liquid to/from the infusionbag 10.

Within the frame of the invention the injection port 26 may be designedin different ways depending on which injection component is to beconnected. In the illustrated embodiment the injection port 26 has afirst flexible membrane 28 for co-operation with a second flexiblemembrane (not illustrated) arranged in an injection component 29 whichis connectable to the injection port 26. The first membrane 28 issuitably air- and liquid proof and penetratable by an injection needle.To achieve a sealed connection of such a injection component 29 to theinjection port 26, the injection part has a means 30 for holding saidsecond flexible membrane with a pressure against said first flexiblemembrane 28. This holding means 30 may for example be constituted by asnap lock device, bayonet coupling or similar. The current pressure inquestion may suitably be chosen so that said first and second membranesare pressed together to a pressure exceeding the yield point of the bothmembranes, which implies that fluid cannot be pressed out through thecontact surfaces of the membranes and a sealed connection is obtained.

If a pressure exceeding the yield point is applied the membranes willexhibit same properties at the compressed surfaces as in an arbitrarycross-section through the membranes, which implies that liquid cannot bepressed through the contact surfaces of the membranes. Such acharacteristic may be obtained when the said first and second membraneshas been pressed together to a pressure exceeding 150 kPa. Since thedevice risks to be destroyed if it is subjected to exceedingly largecontact forces, the contact pressure should be restricted as much aspossible. It has been proved in experiments that the sufficient sealingwithout any risk of failure is obtained with contact forces of up to 11,1N, which corresponds to 656 kPA. Preferably, the contact pressure iswithin the interval 300-473 kPa.

At one end of the first coupling component 13, which end exhibits theconnecting means 15 for establishing communication with the furtherchannel 19 of the second coupling component 14 of the infusion bag 10,the second channel 18 has a inlet 31. Furthermore, the first couplingcomponent 13 has in the other end thereof a port 32 which works as anoutlet for the second channel 18. Within the frame of the invention theoutlet port 32 may be designed in several different ways depending onwhich unit is to be connected to the outlet port. For example a snapcoupling 33 may be used in combination with a friction joint forretaining a connection unit at the outlet port. In accordance with anvariant thereof the entire coupling component 13, or at least the part13 a closest to the outlet port 32 a of the coupling component 13, maybe made of a first material and the connection unit 34 corresponding tothe outlet port may be made of a second material. In this connection,materials having considerably different elasticity may be chosen,preferably so that the second material has a considerable higherelasticity than the first material for providing sufficient sealingaction between the coupling component 13 and the connection unit 34 andat the same time achieve that the coupling component 13 having a lowerelasticity has a high resistance against deformation.

In the extension of the further channel 19, i.e. In a combined inlet andoutlet 35 of the infusion bag 10 a breakable fluid barrier plug 36 isarranged. In a state of not has been broken the fluid barrier plug 36prevents in-flowing and out-flowing via the combined inlet and outlet 35of the infusion bag 10 which implies that the infusion bag 10 is sealed.After connecting the infusion bag 10 to the coupling component 13according to the invention, and eventually to other components, thefluid barrier plug 36 may be broken so that the combined inlet andoutlet 35 of the infusion bag 10 be opened towards the both channels 17,18 in the coupling component 13 according to the invention.

The method according to the invention comprises connecting of a couplingcomponent 13 having two channels 17, 18 for conveyance of medicalsubstances in two substantially opposite directions to a second couplingcomponent 14 of a container 10, such as a infusion bag 10, which secondcoupling component has a further channel 19. After the couplingcomponent 13 and the container 10 have been connected to each other, thecontainer 10 be opened by means of a member 36, preferably in the formof a breakable fluid barrier plug or similar, which member is suitablyarranged in a combine inlet and outlet 35 of the container 10, towardsthe both channels 17, 18 for enabling transportation of a medicalsubstance to the container 10 via one first 17 of said two channels, andfor enabling transportation of a medical substances from the container10.

Preferably, the first 13 and the second 14 coupling components areconnected to each other by a thread joint 15. By means of the threadjoint 15 a male fitting 16 of the first component 13 may be brought intocontact with a corresponding female fitting 22 of the second component14 to form a connection sealed relative to the environment between saidtwo channels 17, 18 and the further channel 19 of the second couplingcomponent 14.

Then, the container 10 be opened towards 17, 18 by breaking thebreakable fluid barrier plug 36. Thereafter, a medical substance may beinjected to the container via one first 17 of said channels.Advantageously, the medical substance is injected by means of acomponent via a port arranged in the first coupling component which porthas a first flexible membrane for co-operation with a second flexiblemembrane arranged in the injection component. Preferably, said secondflexible membrane is held against said first flexible membrane with apressure during the injection to prevent leakage and wastage during theinjection. It has been proved that by holding said second flexiblemembrane against said first flexible membrane with a pressure exceedingthe yield point of the first and second membranes it is ensured that themembranes fit tightly to each other in such away that fluidtransportation between these membranes is prevented and thereby leakageto the environment is avoided. Parallel with the injection, the liquidstate medical substance in the container may be transported via thesecond 18 of said two channels to a receiving unit.

It is stressed that the invention is not restricted to the exemplifyingembodiments; rather within the scope of protection defined by thefollowing claims, the invention may be varied in several ways once theidea of the invention is disclosed.

The invention claimed is:
 1. An infusion arrangement comprising aninfusion bag provided with a coupling for transmitting a medical fluidfrom an injection component to the infusion bag and for transmitting amedical fluid from the infusion bag to a receiving unit connected to thecoupling, wherein said coupling comprises: a first coupling componenthaving two channels for conveyance of medical fluids in two oppositedirections; a second coupling component having a third channel with alumen; and a means for releasable connection of the first and the secondcoupling components to each other for creating the coupling, wherein thereleasable connection means is a thread joint and said third channel isprovided with a breakable fluid barrier that is arranged to remainintact during connection and upon complete engagement of the firstcoupling component to the second coupling component, wherein thebreakable fluid barrier is contained within the lumen of the thirdchannel, whereby the breakable fluid barrier is arranged to beirreparably broken after said connection has been made when it isdesired to transmit medical fluid through the coupling.
 2. An infusionbag comprising a coupling for transmitting medical fluids, wherein saidcoupling comprises: a first coupling component having two channels forconveyance of medical fluids in two opposite directions; and a secondcoupling component having a third channel; wherein said first couplingcomponent and said second coupling component are capable of beingreleasably connected to each other via a thread joint, thereby creatingsaid coupling, wherein said third channel comprises a lumen providedwith a breakable fluid barrier that is arranged to remain intact duringconnection and upon complete engagement of said first coupling componentto said second coupling component, wherein the breakable fluid barrieris contained within the lumen of the third channel, whereby saidbreakable fluid barrier is arranged to be irreparably broken after saidconnection has been made when it is desired to transmit medical fluidthrough said coupling.
 3. The infusion bag of claim 2, wherein saidfirst coupling component comprises a male fitting provided with said twochannels and said second coupling component comprises a correspondingfemale fitting provided with said third channel, to form saidconnection, wherein said connection is sealed relative to theenvironment between said two channels and said third channel when saidfirst coupling component and said second coupling component areconnected to each other.
 4. The infusion bag of claim 3, wherein saidfirst coupling component comprises a ring concentrically arrangedrelative to said male fitting and at least partly enclosing said malefitting, wherein said ring comprises a first thread constituting part ofsaid thread joint, and wherein said female fitting comprises a secondthread corresponding to said first thread and constituting part of saidthread joint.
 5. The infusion bag of claim 2, wherein said firstcoupling component is provided with an opening for injection of amedical substance to a first of said two channels.
 6. The infusion bagof claim 2, wherein said first coupling component is provided with anopening for injection of a medical substance to a first of said twochannels, wherein said opening is closed with a first piercable flexiblemembrane for abutting cooperation with a second flexible membrane of aninjection component that is connectable to said opening, wherein saidfirst piercable flexible membrane is configured to be pierced by aninjection needle after said injection component is connected to saidopening.
 7. The infusion bag of claim 6, wherein said coupling comprisessaid second flexible membrane, and wherein said second flexible membraneis held with a pressure against said first piercable flexible membrane.8. The infusion bag of claim 7, wherein said pressure exceeds 150 kPa.9. An infusion arrangement comprising an infusion bag provided with acoupling for transmitting a medical fluid from an injection component tosaid infusion bag and for transmitting a medical fluid from saidinfusion bag to a receiving unit connected to said coupling, whereinsaid coupling comprises: a first coupling component having two channelsfor conveyance of medical fluids in two opposite directions; and asecond coupling component having a third channel; wherein said firstcoupling component and said second coupling component are capable ofbeing releasably connected to each other via a thread joint, therebycreating said coupling, wherein said third channel comprises a lumenprovided with a breakable fluid barrier that is arranged to remainintact during connection and upon complete engagement of said firstcoupling component to said second coupling component, wherein thebreakable fluid barrier is contained within the lumen of the thirdchannel, whereby said breakable fluid barrier is arranged to beirreparably broken after said connection has been made when it isdesired to transmit medical fluid through said coupling, wherein saidcoupling is configured to permit movement of medical fluid from saidinjection component to said infusion bag via one of said two channels,and wherein said coupling is configured to permit movement of medicalfluid from said infusion bag to said receiving unit connected to saidcoupling via the other of said two channels.